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SyncServer 600 Series User’s Guide
098-00720-000 Revision B – April, 2016
Appendix E IP Port Details
Timing Port Rules
SMTP: inbound and outbound TCP packets on port 25
DNS: inbound and outbound UDP and TCP packets on port 53
DHCP: inbound and outbound UDP packets on port 67 and 68
SNMPTRAP: inbound and outbound UDP packets on port 162
Note that the rules allow inbound packets only, outbound packets that are part of the
session are allowed to go out of the port.
Timing Port Rules
The three timing ports allow the following types of IP packets.
NTP: inbound and outbound UDP packets on port 123
The timing ports use the following types of IP packets, but the ports do not show as
open on a port scanner:
DHCP: inbound and outbound UDP packets on port 67 and 68